We use two steps: 1. Insert a medical-grade endoscope through the spark plug hole to visually inspect cylinder wall scratches and carbon buildup on the piston top; 2. Extract an engine oil sample to check for large metal debris or emulsification (caused by coolant leakage).

Our bulk discounts are not simply calculated by the number of units, but by shipping batches. Typically, consolidating enough for a 40-foot container (which can hold 2-3 vehicles, depending on size) can waive some logistics fees; purchasing more than 5 units at once triggers tiered discounts.

If there is a minor leak in the lines due to bumps, it is possible that the cooling may not work upon arrival. This is a normal physical loss. The cost of vacuuming, pressure testing, and recharging refrigerant at a local auto repair shop is low and is the buyer's responsibility.